Pressure regulating apparatus



.- p 3 R. A. HETZE'R 2,171,699

PRESSURE REGULA'I'ING APPARATUS ,Filed Jan. 25, 1938 I 7 FIG. 2

INVENTOR FUSSELL A. HETZER mww w ATTORNEY Patented Sept. 5, 1939 UNETEQ STATES iATENT @FFEQE PRESSURE REGULATING APPARATUS Application January 25, 1938, Serial No. 186,849

8 Claims.

This invention relates to a vessel or system in which a volatile liquid or solvent is being stored or utilized and more particularly to im proved means for regulating pressure conditions within the vessel or system.

The object of the invention is to provide an improved apparatus for automatically compensating for otherwise wide fluctuations of pressure within a vessel or system, or in other words, for maintaining a fairly uniform pressure so that the parts of the apparatus can be designed and made of material of the proper strength but with minimum weight and cost as well as for further advantages which will more fully appear hereinafter.

In the drawing which represents one suitable embodiment of my invention:

Fig. 1 is a diagrammatic view of a dry cleaning system, parts being broken away to expose the internal structure, and showing my improved regulator in diagrammatic form associated therewith.

Fig. 2 is an enlarged cross sectional view of my improved regulator and a portion of the reclaiming unit of a dry cleaning system, showing parts of the regulator in elevation and the operating mechanism for the regulator in diagrammatic form; and

Fig. 3 is a side elevational View of a motor, showing the drive connection between the motor shaft and a pinion for operating the regulator.

One common form of dry cleaning apparatus utilizing volatile detergents comprises a chamber or casing within which garments or fabrics to be treated are subjected to the effects of a quantity of a liquid detergent, following which the liquid detergent is drained off and extracted from the fabric as much as possible and any remaining detergent is removed by the use of an air current, is condensed and returned to the liquid, and the used liquid detergent is cleaned or clarified by distillation and condensation. While any volatile detergent may be employed, one common detergent suitable for the purpose is carbon tetrachloride.

Systems of this kind if entirely closed or sealed against escape of vapors to the atmosphere necessarily must be made of heavy material. This is true not only of the casing or walls of the treating compartment but also of the walls of containers for liquid, stills, condensers and the like. The reason is that the chambers within the several vessels necessarily are subjected to widely varying fluctuations of pressure if the entire system is sealed or closed, due to the application of heat for distillation, the variations in temperature of the outside air, and also variations in temperature of the cooling medium, such as water and the like. As a result most systems are provided with an open vent to the atmosphere to maintain atmospheric pressure or nearly so, within the system, with the disadvantage of possible loss of valuable detergent by free escape to the atmosphere.

The present invention is designed to prevent loss of valuable detergent by escape to the atmosphere incident to the use of a vent by closing or sealing a vessel or system against venting or escape to the atmosphere except during loading or unloading and at the same time providing the vessel or system with means which automatically compensate for the Wide fluctuations in pressure which otherwise would be produced in such a vessel or system. In case of abnormal pressure conditions existing in the vessel or system, however, my improved apparatus acts as a vent and permits vapors to escape when the pressure becomes abnormally high or allows atmospheric air to enter the vessel or system if the pressure becomes abnormally low.

While my improved pressure regulating means may be employed in any vessel or system in which a volatile solvent or detergent is being stored or utilized, for purposes of illustration the system shown in the drawing comprises a treating unit I, a detergent storage tank 2, a still 3, a condenser 4 and a sump tank 5 suitably connected and associated with each other.

The treating unit I is somewhat similar to an ordinary washing machine or drying tumbler and comprises an outer casing 6 and an inner rotatable foraminous drum '5 within the chamber of the casing. Connected in circuit with the casing is a condenser 8 whose inlet side communicates by a conduit 9 with the casing 6, an 40 air moving device, such as a fan ID, the inlet side of which is connected to the condenser by means of a conduit H, and a heater l2, the inlet side of which is connected to the outlet side of the air moving device by a conduit l3 and the delivery side of which is connected to the casing by a conduit l4 provided with a valve I5.

Liquid detergent is supplied to the treating chamber by way of-a supply pipe I6 having a valve ll, said supply pipe communicating with the 5 storage tank 2. The used liquid in the treating chamber 1 may be drained therefrom to a sump tank 5 by way of a pipe I8 provided with a valve l9. Sump tank 5 communicates by means of pipe 2|] having a valve 2| with the evaporator or still cooling coil 25 through which cold water may 7 be circulated. The liquid thus condensed flows by way of pipe 26 to the storage reservoir 2.

With this arrangement the material to be treated is first loaded into the rotating drum i and a quantity of liquid detergent is run into the treating compartment by opening valve i'i which is then closed. The drum 1 is rotated for the proper period of time to produce a thorough agitation of the material in the detergent with a consequent washing or cleaning thereof. Finally, the drum 1 is stopped and the liquid in chamber i is drained to the sump tank 5 by opening valve i9. When as much liquid has been extracted and drained from the work as is reasonably possible, the fan 59 is started, air from the treating chamber I is circulated through the condenser 8 by the fan Hi, returning by the way of heater i2 and conduit M to the treating chamber, solvent vapors being condensed and flowing by way of conduit 21 to sump tank 5. This drying operation is continued until substantially all the detergent has been recovered.

Conduit i3 is provided with a connection 28 to the atmosphere to be opened and closed by a valve or damper 29. The valve E5 in conduit i l and valve 29 are operatively connected by means of a link 32 and may thus be jointly operated. During the washing and drying operation before referred to the valves lie in the full line position as shown in Fig. 1. When the drying operation is finished valve i5 is moved to open position and valve 29 shuts oif communication between the air moving means IE9 and the heater i2. Therefore when the drying operation is concluded, the fan continues to operate for deodorizing, drawing fresh air in through valve I 5 from which it flows through the treating vessel l and condenser 8 to the atmosphere through pipe 28. Valve 2| is now opened and the liquid in sump tank 5 is drained into the evaporator, is there distilled and is conveyed as a gas tocondenser 4 from. which as a liquid it drains to storage tank 2.

As illustrated in the drawing the pressure within the various vessels of the system is equalized and means are provided to regulate fluctuations in pressure within the system. As shown,

a vent pipe 33 leads from the sump tank 5 and is provided with a branch. 34 which is connected to casing 6 and a branch 35 which is connected to storage tank 2.

When liquidis passed into the treating vessel i from tank 2 the vapors displaced in the treating vessel pass to tank 2 through branches 3d and 35 of the vent pipe, and when liquid is passed from. treating vessel i to sump tank 5 vapors displaced in sump tank 5 flow to the treating vessel through vent pipe 33 and branch pipe 36. In a like man ner when liquid is drained from sump tank 5 into the evaporator or still 8, the vapors displaced in the evaporator pass through conduits 23 and 26 and vent pipes 35 and 33 to sump tank 5.

My present invention provides means for regulating the pressure conditions within the system and also acts: as a vent when abnormal pressure conditions occur within the system. As shown in Fig. 2 my improved apparatus comprises a tank 36 containing any suitable liquid, such as tank water, which tank for convenience is shown mounted upon condenser Arranged within the tank in spaced relationship thereto and mounted for vertical movement therein, is a container 3'2 having a bottom opening 38, the lower end of which container normally extends below the level of liquid in tank 5t, thereby form ing a gas chamber 352 into one end of which a pipe ii extends, the other end of pipe 45 being in communication with the chamber of storage The vertical movement of container 3? is guided by means of rolls ii which are rotatably mounted in brackets attached to the side of the tank and are preferably spaced 90 apart and also by means of a bracket 42 having an aperture '53 through which a rack 44 secured to the container passes during the vertical movement of the container. The rack id is provided with a marker which is placed in registry with a pointer 45 attached to bracket 42 when drum 1 is open to the atmosphere, such as when fabric is being introduced into or removed from drum 9. At this time the liquid in tank 35 and container 3-? at the same level and forms a liquid gas chamber 39 and the atmosphere. rdance with my invention means are raise or lower tank 3? when the presn storage tank 2 or within the system tends to vary. While any suitable means responsive to pressure conditions existing within the vessel or system may be employed, as illustrated in the drawing, an electric motor 47, having a pinion i'ia connected to its shaft which is in meshing engagement with rack 44, is provided and power is supplied to operate the motor in one direction when the pressure Within the vessel or system tends to rise above atmospheric pressure, and in the opposite direction when the pressure within the vessel or system tends to fall below atmospheric pressure. Motor ll is of the gear head type in which irreversible speed reducing gearing is provided, that is, the gearing not only reduces the speed at which the rack is reciprocated but prevents the rack from operating the motor.

As shown diagrammatically in the drawing the vent pipe 33 is in communication with a diaphragm 18 arranged within a housing 49, which housing also contains a mercury switch 5i sup ported by a bracket 5i pivotally mounted at the point 52. Extending upwardly from diaphragm A8 is a rod 53 which is connected to a lever 54 pivotally mounted at the point 55, one end of lever 54 being provided with a link 56 which is connected to one end of bracket 5! and the other end of the lever being mounted between compression springs 5'! and 58 which are suitably supported in the housing.

With this arrangement, when the vapor pressure tends to rise in the system diaphragm. 48 expands, moving lever 54 in a clockwise direction and tipping mercury switch 56 in an anticlockwise direction, thereby forming an electrical connection between terminals 59 and 65 and contracts, the mercu y switch is returned to its ;rmal position and the electric circuit is broken.

In the event that pressure conditions within .e system tend to fall, diaphragm 48 contracts, ver 54 is moved in a counterclockwise direction sainst the compressive force of spring i and .e mercury switch is rotated in a clockwise rection, thereby forming an electrical connecon between electrodes 5'5 and E8 and establish-- .g a circuit from line L1 through conductor 59, ectrodes 63 and 67, conductor it, coil Ti and nductor 12 to line L2. The energization of coil 1 closes magnetic switch 73 and current is sup-- .ied to the motor from lines L1 and L2 through nductors 65 and $5. The motor is therefore aerated in the reverse direction and tank Bl lowered. Diaphragm 48 then expands. the

.ercury switch is returned to its normal position rid the electric circuit is broken.

For normal fluctuations which occur in sys- :ms of this type, it is not necessary to raise the ottom opening of container 31 above the liquid :vel in tank 36. A breathing action is therefore rovided as container 3? is raised and lowered nd the pressure within the vessel or system is iaintained substantially constant. In the event iat the increase in volume in chamber 355 effecta. by raising container 37 without breaking the quid seal does not compensate for the increase 1 pressure within the system, the container is aised above the level of the liquid and pipe to l vented directly to the atmosphere. In case bnormaliy low pressure conditions occur with- 1 the system, the top of container 3'! is lowered gainst the terminal of pipe to and atmospheric ressure forces the liquid between container nd 35 downwardly a suificient extent to allow ir to flow through the bottom opening in the ontainer.

When the top of container 31 rests upon the erminal of pipe 46, motor 41 will still continue o operate if. the pressure within the system is elow normal. To prevent damage by this action, iotor 3? is connected to pinion 41a by means i a friction clutch, one element 15 of which is plined to the motor shaft and is yieldingly held o engagement with the other element 16, the rub of which engages a support ll. During normal operation, a compression spring 18 forces lutch element i5 into suflicient frictional en- :agement with clutch element 16 to translate moion from the motor shaft to pinion 41a. When he top of container 31 engages the terminal of ipe 0, however, and the motor still continues to iperate, spring 18 does not exert suificient com- :ressive force to prevent clutch element 15 from .lipping.

The pipe 40 is provided with side openings 79 vhich allow air to pass through pipe 40 when be top of the container 31 rests upon the end of shoe 4%, and the height of tank 36, container 3?, rent tube 48' and the level of the sealing liquid in ;ank 33 are such that during normal fluctuation if pressure within the tank or system the liquid extends above the lower end of container 31, has forming a liquid seal which is broken if the .ncrease in volume of chamber 39 is not suflicient )0 compensate for the tendency of the pressure 30 rise. The level of the liquid, however, should not be such that it will enter the orifice of vent pipe 49 when abnormally low pressure conditions exist in the vessel or system.

Means are also provided to maintain the liquid in tank 33 at a substantially contant level and to compensate for any liquid which evaporates. For this purpose a liquid supply conduit 82 having a valve 83 is provided, said valve being actuated by a float 84 when the liquid in tank 36 falls below a predetermined level. An overflow pipe 85 is also provided to prevent the liquid in tank 36 from rising above a predetermined level. With such an arrangement liquid is supplied to tank 36 as it evaporates. It is also supplied to tank 36 when abnormally low pressure conditions exist in the vessel or system and the level of the liquid in the space between tank 36 and container 31 is lowered, but as such conditions generally occur suddenly, the small amount of water supplied through conduit 82 is not sufficient to raise the liquid in container 31 to such a level that it flows through conduit 48 before the vacuum conditions within the vessel or system are relieved.

To set container 3'1 at the proper position as indicated by the mark 45 on rack 44 and the pointer 46 on bracket 42, when normal or atmospheric pressure exists in the system, as for example when fabric is being introduced or removed from treating chamber l, plugs 86 and 81 are provided, which are normally maintained in open position. When plug 86 is pressed, a circuit is connected in parallel with the circuit established by terminals 59 and 58 of the mercury switch and current is supplied to motor 41 to raise container 37, and when plug 81 is pressed a circuit is connected in parallel with the circuit established by the terminals 6'! and 68 of the mercury switch and current is supplied to the motor to lower container 31.

What I claim is:

1. Apparatus of the class described comprising a vessel or system having a chamber containing a volatile solvent and subjected to influences tending to vary the pressure in said chamber and means for maintaining substantially uniform pressure in said chamber comprising a container having a gas chamber, motor means responsive to pressure conditions within said vessel or system for increasing and decreasing the volume of said gas chamber as the pressure within said vessel or system tends to rise and fall, and communicating means between said chambers.

2. Apparatus of the class described comprising a vessel or system having a chamber containing a volatile solvent and subjected to influences tending to vary the pressure in said chamber and means for maintaining substantially uniform pressure in said chamber comprising a container having a gas chamber, electrically operated means responsive to pressure conditions within said vessel or system for increasing and decreasing the volume of said gas chamber as the pressure within said vessel or system tends to rise and fall, and communicating means between said chambers."

3. Apparatus of the class described comprising a vessel or system having a chamber containing a volatile solvent and subjected to influences tending to vary the pressure in said chamber and means for maintaining substantially uniform pressure in said chamber, comprising a tank containing a liquid, a container having a bottom opening mounted for vertical movement in said tank, the lower end of said container being normally below the level of liquid in said tank during its vertical movement, thereby forming a liquid seal and a gas chamber in said container above said liquid, communicating means between the chamber of said vessel or system and the gas chamber of said container, and motor means responsive to pressure conditions within said vessel or system for raising and lowering said container to increase or decrease the volume of said gas chamber when the pressure within the vessel or system tends to rise or fall.

4. Apparatus of the class described comprising 3 a vessel or system having a chamber containing a Volatile solvent and subjected to influences tending to Vary the pressure in said chamber and means for maintaining substantially uniform pressure in said chamber, comprising a tank containing a liquid, a container having a bottom opening mounted for vertical movement in siad tank, the lower end of said container being normally below the level of liquid in said tank during its vertical movement, thereby forming a liquid seal and a gas chamber in said container above said liquid, communicating means between the chamber of said vessel or system and the gas chamber of said container, and means responsive to pressure conditions within said vessel or'system for raising or lowering said container to increase or decrease the volume of said gas cham- 'to compensate for the tendency of the pressure ber when the pressure within said vessel or system tends to rise and fall, said means being effective in raising said container above said liquid when the volume of said container is insufficient to rise in said vessel or system.

5. Apparatus of the character described comprising a vessel or system having a chamber containing a volatile solvent and subjected to influences tending to vary the pressure in said vessel or system, means for maintaining substantially constant pressure in said chamber during normal operations comprising a tank containing a liquid, a container having a bottom opening mounted for vertical movement in said tank, the

said container, the level of liquid in said tank being such that when abnormally low pressu: conditions occur in said vessel or system, a from the atmosphere breaks the liquid seal ar vents the vessel or system. i

6. Apparatus of the class described compri: ing a vessel or system having a chamber cor taining a volatile solvent and subjected to ix fluences tending to vary the pressure in sai chamber and means for maintaining substar. tially uniform pressure in said chamber compri: ing a tank containing a liquid, a container hav ing a bottom opening mounted for vertical move ment in said tank, the open end of said containe being normally below the liquid level in sai tank thereby forming a closed gas chamber, com municating means between the chamber of sai vessel or system and said gas chamber, and elec trically operated means responsive to the pres sure in said vessel or system for raising or lower ing said container to increase or diminish th volume of said gas chamber.

7. Apparatus of the class described comprisin; a vessel or system having a chamber containin; a volatile solvent and subjected to influence tending to vary the pressure in said chambe and means for maintaining substantially uniforn pressure in said chamber comprising a tank con taining a liquid, a container having a bottom opening mounted for vertical movement in sair tank, the open end of said container being normally below the liquid level in said tank, thereby forming a closed gas chamber, communicating means between the chamber of said vessel or system and said gas chamber, a diaphragm casing forming a chamber, communicating means between the chamber of said vessel or system and said diaphragm chamber, said diaphragm casing being adapted to expand when the pressure within said vessel or system tends to rise and contract when the pressure within said vessel or system tends to fall, and means responsive to the movement of said diaphragm for raising or lowering said container to increase or diminish the volume of said gas chamber.

8. Apparatus as set forth in claim 3, including means for maintaining the level of liquid in said tank substantially constant.

RUSSELL A. HETZER. 

